


Little Sister

by AngelynMoon



Series: Making a family [4]
Category: Marvel Cinematic Universe
Genre: Alpha/Beta/Omega Dynamics, Breastfeeding, Communicating with your partner; let's make that a tag guys, Families of Choice, Gen, M/M, Male Lactation, Post Mpreg, mentioned/implied
Language: English
Status: Completed
Published: 2020-03-30
Updated: 2020-03-30
Packaged: 2021-03-01 04:53:54
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 3,842
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23399518
Author URL: https://archiveofourown.org/users/AngelynMoon/pseuds/AngelynMoon
Summary: The Avengers and Avengers adjacent meet a little Dream.As always let me know for tags.
Relationships: James "Bucky" Barnes/Steve Rogers, Minor or Background Relationship(s), Natasha Romanov/Sam Wilson, Pepper Potts/Tony Stark
Series: Making a family [4]
Series URL: https://archiveofourown.org/series/1673449
Comments: 10
Kudos: 117





	1. Chapter 1

Steve didn't make breakfast. Tony frowned, Steve had, since he had moved in, always made breakfast in the mornings, sometimes Darcy assisted but she'd said she hadn't seen Steve this morning.

Bucky wasn't up either, normally he could be found with his arms around Steve's waist as the other man cooked, when he wasn't standing behind Steve he was moving plates of food to the table.

But today they weren't there, J.A.R.V.I.S., when asked had informed them that the two were still in bed.

Clint had figured that Steve's first time staying behind had made him sad and they had decided to sleep in a little but Tony had a feeling it was something else.

They waited an extra few minutes while J.A.R.V.I.S. informed Steve and Bucky that breakfast was ready if they wanted to come up.

When they arrived Steve was walking a little oddly, and Bucky had his arm around his waist like he was holding him up. Steve's arms were across his chest and something was wrapped in a blanket.

Tony saw it wriggling and he had a very firm no pets policy.

"No pets." Tony shouted as he pointed at the blanket.

Bucky glared at him, and wow Bucky hadn't given him that look since he'd dragged Tony through Steve's hospital door.

"She's not a pet anymore than you are." The former assassin said.

Steve laughed softly and shifted his hold and that was an arm..., a baby's arm.

"Where'd you guys get a baby?" Clint screeched excitedly as he ran over to look at the baby Steve was holding, Steve shifting so he could see them better.

Sam, Darcy and Thor were quick to join them with Bruce and Pepper hanging back.

"They're adorable." Darcy cooed as she placed her finger in a tiny hand.

"She." Bucky said softly as he extracted Darcy's finger and guided Steve to the table, helping him sit and then loading up a plate for him.

The others joined them as Bucky scooted his chair close to Steve's letting the other man lean against him.

"You gonna feed her here?" Bucky asked softly against Steve's hair.

"We don't have any formula in the kitchen." Brice said and of course they didn't, they didn't know there was a baby in the Tower.

Steve shook his head, ignoring them, "I fed her while you took a shower."

Bucky nodded and then proceeded to feed Steve while the man just held the baby, Tony would have liked to say that was unusual but they fed one another quite often.

"So, you know you could have told us that you were adopting, we would have helped out, getting your rooms ready, or...Pepper would have loved baby shopping." Tony said as he picked at his plate.

Did they really not trust them enough to tell them that they were expanding their family?

"Tony, we didn't adopt Aisling." Steve said softly as he shifted her up and looked at Tony.

"Then...um...how...?" Bruce stammered because it was not possible for two Alphas to have a baby together naturally.

Sam and Natasha chose that moment to burst into laughter.

Tony waited for the laughter to die away before he stared at them, "What do you two know?"

The two looked at one another and then at Steve who just rolled his eyes as the baby fussed.

"The 40's people were dicks." Bucky said as he traced the baby's cheek.

"Bucky!" Steve shouted as he turned to glare at his lover, "Watch your mouth, there are ladies and babies present."

Bucky rolled his eyes and continued, "Phillips and the rest of the senators thought moral would take a dive if the public discovered that Captain America was an Omega, so they marketed him as an Alpha. Bunch of shi-" Bucky glanced at Steve and changed the word he was about to use, "Bogus if you ask me, but then Steve wasn't the ideal Male Omega anymore. Punk actually thought that mattered to me." Bucky finished with a kiss on Steve's hair.

"So, what you're saying is that Steve is an Omega?" Darcy said slowly.

"Yeah, kiddo." Bucky grinned at her.

"Oh my god, you have been adopting us!" Darcy shouted, "I thought you were just being protective and weird."

"Nope, instincts say you're all our kids." Bucky informed them.

"But Thor's older than you!" Tony shouted.

"The way we figure Asgardian aging, Thor's only about twenty." Bruce interrupted.

"But..but.." Tony tried to think.

"Tony, you're under no obligation to reciprocate." Steve said gently, reaching out to hold Tony's wrist, "It just means we care."

Tony stared and looked away.

"So, Steve gave birth?" Jane asked with a frown, "Is he okay, should we get a doctor?"

Bucky shook his head, "Steve says he's mostly healed, just a bit sore. I trust him to know, this is hardly the first time we've done this."

Pepper frowned, "But you don't have children." She said slowly.

Steve stiffened and Bucky murmured something soothing that they ignored.

Bucky looked at her, half glaring, "We do, just because none of the ones Steve carried lived before Aisling doesn't change their existence." 

Pepper nodded, "I'm sorry, I didn't mean it that way."

Steve put a hand on Bucky's cheek, "We know. It's still hard to be reminded."

There was a long silence before Tony broke it.

"So, can I hold my little sister or are we waiting?" Tony asked.

"Hey, I wanna hold her too, why does Tony get to first?" Clint whined.

"As the oldest I should get to hold her first." Thor boomed as he stood up.

And they watched as the rest of the table broke out into a fight over who got to hold Aisling first.

Steve looked at Tony who was watching the fight silently and tugged at the wrist he was still holding.

Tony moved closer and Steve settled the baby in his arms, adjusting them to cradle the small child but not removing his hand from her head, for a moment Tony thought he didn't trust him before he remembered that Steve had lost at least one or two other babies, it probably still didn't feel quite real to him.

"What's her whole name?" Tony asked, "Please tell me her middle name is America."

Bucky turned his head as Thor threw Clint into the coffee table and Darcy argued with Jane that she was the best one to be the first to hold the baby, Natasha was wrestling with Sam and shouting in Russian.

"I'm gonna go take care of that." Bucky said as he extracted himself from Steve to handle the fighting that was destroying the living area.

Steve smiled at him as he left and then turned to Tony.

"It's Aisling Antonia Barnes." Steve said softly as he caressed her tiny head.

"You named her after me?" Tony asked, something catching in his throat.

"It's a tradition in some families to name a child after their oldest sibling, Bucky can't remember what he named the other ones and the one I named is named for his father so, yes, we named her after you." Steve explained and then paused, "If that's alright with you, we haven't done her birth record yet so we can change it if you don't like it."

Tony looked at Steve, "I like it, thank you." Tony then grinned widely, "I'm so calling you mom." 

Steve smiled and hugged Tony carefully, "I'd actually like that very much, Tony."

"Oh." Tony said, he'd meant to do it teasingly but if Steve was alright with it then Tony would do it seriously, "Okay, mom."

There was a few moments of silence as Bucky glared the others into cleaning the messes they'd made and marched each one to a blank expanse of wall for time outs, apparently there weren't enough corners and Tony had to chuckle at the sight of Pepper standing primly in a corner near a pouting Darcy.

"Why's my arm wet?" Tony asked as he felt something dripping through the blanket.

\--

A/n: Steve doesn't know about disposable absorbent diapers yet or even insert cloth diapers so he just sort of wrapped Aisling up and hoped for the best, also she was sort of unexpected, Steve hadn't bought anything for her because he didn't want to jinx it.

Yes Aisling peed on Tony, no it doesn't stop him from holding her in the future.

Name meanings-

Aisling - Gaelic, fantasy/dream

Antonia - English, Italian, Latin, Spanish, invaluable

Also I thought about naming Aisling after Coulson but I didn't like the feminine versions of his name or the ones that were similar to it and it's considered bad luck to name a child in memory of someone still living, since Peggy is still alive they couldn't name Aisling in her memory.

Naming Aisling after Tony is meant to connect them since there is such an age gap, also since it's her middle name and her brother it's slightly more acceptable.


	2. Chapter 2

Steve won't let Aisling out of his sight, hardly allows anyone else to even hold her, not even Bucky.

Steve is also exhausted.

Babies are exhausting, Tony knows that, he was signed up for the mandatory Alpha/Beta/Omega classes as a child before he graduated high school and hid in College, where they spent a third of the year role playing as the different Dynamics. Back then Tony had hated how easy the Alphas and Betas had it, half the time during the Omega trimester they'd had to wear a fake baby belly and then had to take care of one of those fake babies that were easy to reprogram, not that Tony reprogrammed his to be on a set schedule, that would have been cheating.

But back to the baby, Tony could tell that Steve was half a second away from falling asleep with the baby that was still eating while she dozed off.

"Hey." Steve said tiredly, "I didn't think anyone was still here."

Tony shrugged, "I got hungry."

"I can make you something." Steve said before yawning.

Tony laughed, "I'm good." He held up his sandwich, "But I'll take the baby."

Tony made grabby hands.

Steve laughed a little, Tony had shocked almost everyone with how much he delighted in holding Aisling, even after she peed on him.

Tony would have been insulted if he hadn't been right there with them but seeing him with a baby made Pepper get this look in her eyes and though she hadn't brought it up yet Tony had started gathering information on surrogacy and in-vitro treatments.

Steve detached the baby and burped her, offering the whining child to Tony as he sat next to Steve on the couch.

"I just changed her and she's eaten, she should be good for a bit." Steve told him.

"I know how to take care of a baby, I did pass the class in high school." Tony told him, rolling his eyes.

"What class?" Steve frowned.

"It's a stupid class designed to 'prepare' you for you dynamic, it's ridiculous because it basically teaches Omegas all they're good for is babies." Tony started and kept going.

Tony trailed off several minutes later when Steve failed to add his opinion and Tony looked over to found that Steve had fallen asleep while Tony ranted.

Tony laughed a little and looked at Aisling, her tiny hand curled over the top of the Arc Reactor.

"Mom must have been really tired." Tony whispered to the sleeping baby.

Tony shifted so he could cage Aisling against the back of the couch and his body, pulling his feet up onto the couch cushions before he pulled out his phone to work on his calculations, telling J.A.R.V.I.S. to warn the others that Steve and Aisling were sleeping.

A couple hours later Tony changed Aisling's diaper and threw the cloth diaper into the basket they had for it, he then rewrapped the baby and tucked her against him before she could start screaming.

"Here." Pepper said softly, offering a small bottle.

Steve often pumped, mostly to get his production up, it meant there was always expressed milk in the fridge to give Aisling a snack if Steve was occupied with something, usually dinner, whenever he was free he'd feed her until she was done.

"Thanks." Tony said, just as soft, mindful of a still sleeping Steve, as he took the bottle and began feeding the baby.

"Come here." Pepper beckoned him, leading him to the loveseat where she settled him against her chest as he fed Aisling, her arm tucked under his to help support the little one that was held there.

"She makes you want to have one of your own, doesn't she?" Pepper asked quietly, into his shoulder.

"I..." Tony started, then stopped, he'd always wanted kids, he was just afraid of how he'd ruin them when it was just him, no family, no support, no one to tell him what he was doing wrong.

"Tony?" Pepper asked.

"Would you want one? Because, yeah, I want kids, but I also want you and if I had to chose it'd be you." Tony admitted, he loved Pepper and if she didn't want kids he'd be fine with that, he'd just have to steal Aisling or one of the others' kids, he could deal with that.

"You can't carry a child, Tony, I've seen your medical records." Pepper told him.

Tony opened his mouth to say something but Pepper continued.

"I could carry the baby, it be a risk because I'm an Alpha but possible, and we'd have to find a clinic willing to do it as well as the possible backlash of an Alpha carrying an Omega's child, stupid traditionalists." Pepper sneered.

Tony sniffled and buried his face in Pepper's shoulder.

"Tony?" Pepper asked, concerned.

"I'm just...I hadn't expected you to have thought about it." Tony admitted, he might have been fully invested but a little voice in his head, one that sounded a lot like Howard, kept telling him he wasn't good enough, that Pepper would get tired of such a high maintenanced and useless Omega and would leave.

"Tony, I'm in this, not leaving." Pepper pressed a kiss to his temple as Aisling finished eating and Tony burped her, wiping away the small amount of spit up.

"We haven't talked about Bonding or Mating." Tony said softly.

"You've always called it archaic, said it made an Omega property." Pepper said, "I didn't want to ask when I knew your opinions."

Tony looked at Steve, Steve who'd been Bonded and Mated when Bucky was captured, Steve who had walked into danger to rescue his Alpha even though everyone had said that Bonded Omegas wouldn't risk a potential child and walk in to a dangerous situation, who had continued to fight by his Mate's side instead of going home. Tony thought about how people said it was impossible for Omegas to kill and he knew that Steve had killed at least one person during the War and if they were wrong about that maybe some of the other things he'd read as a kid and heard his father say were wrong too.

"I think, maybe, I'd like to think about it, talk to Steve a little since he's been Mated and Bonded for a hundred years." Tony said softly.

"We Mated at eighteen, technically we were unofficially Bonded long before that." Steve said as he slowly pushed himself up from the couch, rubbing the sleep from his eyes, "But we were Synced before Bonding too."

"What's the difference?" Tony asked, he hadn't heard an explanation for any of those terms that didn't make him angry, and he had never heard Sync in the context of Dynamics.

"Syncing is when a couple's Heats and Ruts match, I'm not talking timing, I mean intensity. I was always sick, when I had a Heat at all Bucky's Rut was mild, he was in full control, he could tell when we needed to slow down or stop, even during his intense Rut that happened when I wasn't in heat he'd be able to pull back when I was having trouble." Steve explained, "Bonding is something similar, it's like the pre-Mating, when your Instincts start to draw you closer, this is usually the point where couples start having Heats and Ruts near each other. Mating is when you bite one another, usually during a Heat, generally only the Alpha bites but it's better that both do, it basically tells your instincts that 'Yes, this one is ours and we're their's and that's that'. It used to be that proper Syncing happened after Mating." Steve them.

Steve looked at Tony and Pepper, then held his arms out for Aisling, who Tony handed over, Steve beginning to feed her again.

"Bucky and I were all out of order, and I know that some couples now go their whole lives without Syncing properly but I like that we were just that meant for one another." Steve said as he pressed his nose into his daughter's dark wispy hair.

Tony looked at Steve and thought about how fluidly they moved together, like a matched set of give and take.

"How do you tell?" Tony asked, "We have things that prevents Heats and Ruts, how can you tell?"

Steve looked at them, "For Bucky and I we just knew. But you and Pepper are solid, Bucky wouldn't have felt the need to threaten Pepper if she hadn't been serious about you, Tony."

"When did Bucky threaten you?" Tony turned to look at Pepper.

"When he first arrived, I thought it was just a thing, I heard he did the same to Jane, Sam, and Natasha." Pepper shrugged.

"But Natasha is his kid." Tony cried.

"And Sam's family, more of a brother than a son but still family, which means Natasha can only play with his heart so much." Bucky said as he entered the room, continuing through to put the groceries away in the kitchen, pausing to dig out a couple bananas for Steve and to kiss the Omega's lips, touch Aisling's head gently.

"You two are disgustingly sweet." Tony grumbled crossing his arms as he slouched into Pepper.

Steve chuckled and burped Aisling.

"Gimme." Bucky said as he plopped down next to Steve.

Steve hugged the baby tighter to his chest and Bucky sighed but tucked Steve against his chest, leg sliding behind Steve along the back of the couch, the Omega curling up between his legs.

Bucky tucked his arms under Steve's own where they cradled their daughter and pulled him closer, petting Steve's hair with his hair, the Omega falling into sleep again.

"We'll order take out for tonight, the others won't mind, we know Steve's been trying to do everything he usually does plus Aisling, despite the offers to help." Pepper smiled softly at the couple.

"Hey, he let me have her a whole few hours while he took a nap." Tony told them, "Granted I never left the room but he didn't wake up, or if he did he went back to sleep, that's progress." 

"Yeah." Bucky agreed, "I think he's worried that if he loses sight of her she'll disappear."

Bucky pressed a small kiss to Steve's hair.

"I can't blame him." Tony said softly, "If it were me, I'm not sure I'd be able to even let her go period."

"Believe me, that first night he didn't let her go, not even to pee, he made me help so he didn't have to put her down or hand her over. The first I got to hold her was the three minute shower Steve took before breakfast and the additional two it took for him to dress and then he demanded her back afterwards." Bucky chuckled.

"I held her longer than you." Tony said shocked.

"Yeah, but Steve didn't stop touching her either." Bucky half shrugged.

There was a pause and then Pepper got up.

"I'm going to go order dinner, I'll be back soon, why don't you two start a movie." Pepper suggested as she placed a kiss to Tony's lips and the ln left.

"So, what haven't we watched yet?" Tony asked J.A.R.V.I.S. 

"I believe you were working your way through the musicals." J.A.R.V.I.S. intoned, "I believe that The Sound of Music was next on the list but considering the nature of it's contents I do think skipping it may be wise."

"Right, yeah, next." Tony said.

"What's it about?" Bucky asked, curious.

"Nazi's, well no, it's about a novice nun falling in love during the rise of the Nazi party, but there are still some parts that may be sensitive or insensitive as the case may be." Tony explained.

"Right, agreed, next." Bucky said.

"Let's have something somewhat soft, put on Annie, not the new one or the first one, the 1999 version, I like that one best." Tony said.

"What's this one about?" Bucky asked as he shifted Steve against him.

"You'll like it, it's heartwarming." Tony said as the rest of the family came in and settled around.

"That told me nothing." Bucky said rolling his eyes.

"Shh, Bucky, the baby's sleeping." Steve mumbled a little as he cracked an eye open.

"Fine. But if there are nightmares I'm waking you up." Bucky warned as Pepper walked back in and the movie started to play, only pausing for Darcy and Jane to go get the food and sort it out because Steve was feeding Aisling again and none of them were going to let him help even if he wasn't.

They ate and watched the movie and Bucky couldn't help thinking that this was nice.

\--

A/n: there were no nightmares but there were tears.

"He adopted her, Bucky!" Steve sobbed.

"I know, Stevie, I know." Bucky said patting his shoulder.

All of the Avengers and Darcy may have shed some tears too because Warbucks sort of reminded them of Steve and adopting them all too.

I'm adding this to Little Sister because i'm not sure if i want to do the next fic when she's a few years older or a least sitting up and Steve is a little less clingy, we'll see.

I just have to add this here before i forget, Aisling starts to get used to falling asleep.to the hum and light of the Arc Reactor that at one point she refuses to go to sleep without it and Tony has to make a nightlight type version that they put in a teddy bear for her.

It is in the shape of a star and the bear is a Bucky Bear with it set in it's chest because it's not really a Bucky Bear anymore it's a combination of Bucky Bear an Captain America now.

Tony was maybe a little sleep deprived when he made it but Aisling loves it.


End file.
